Crystal bending in triple-Laue X-ray interferometry. Part II. Phase-contrast topography.

In a previous paper [Sasso et al. (2023). J. Appl. Cryst.56, 707-715], the operation of a triple-Laue X-ray interferometer having the splitting or recombining crystal cylindrically bent was studied. It was predicted that the phase-contrast topography of the interferometer detects the displacement field of the inner crystal surfaces. Therefore, opposite bendings result in the observation of opposite (compressive or tensile) strains. This paper reports on the experimental confirmation of this prediction, where opposite bendings were obtained by copper deposition on one or the other of the crystal sides.

Crystal bending in triple-Laue X-ray interferometry. Part I. Theory.

The measured value of the (220) lattice-plane spacing of silicon 28 using scanning X-ray interferometry is essential to realize the kilogram by counting 28Si atoms. An assumption made is that the measured lattice spacing is the bulk value of an unstrained crystal forming the analyser of the interferometer. However, analytical and numerical studies of the X-ray propagation in bent crystals suggest that the measured lattice spacing might refer to the analyser surface. To confirm the result of these studies and to support experimental investigations of the matter by phase-contrast topography, a comprehensive analytical model is given of the operation of a triple-Laue interferometer having the splitting or recombining crystal bent.

Neutron interference from a split-crystal interferometer.

The first successful operation of a neutron interferometer with a separate beam-recombining crystal is reported. This result was achieved at the neutron interferometry setup S18 at the ILL in Grenoble by a collaboration between TU Wien, ILL, Grenoble, and INRIM, Torino. While previous interferometers have been machined out of a single-crystal block, in this work two crystals were successfully aligned on nanoradian and picometre scales, as required to obtain neutron interference. As a decisive proof-of-principle demonstration, this opens the door to a new generation of neutron interferometers and exciting applications.

Defocused travelling fringes in a scanning triple-Laue X-ray interferometry setup.

The measurement of the silicon lattice parameter by a separate-crystal triple-Laue X-ray interferometer is a key step for the realization of the kilogram by counting atoms. Since the measurement accuracy is approaching nine significant digits, a reliable model of the interferometer operation is required to quantify or exclude systematic errors. This paper investigates both analytically and experimentally the effect of the defocus (the difference between the splitter-to-mirror and analyser-to-mirror distances) on the phase of the interference fringes and the measurement of the lattice parameter.

Long-term persistency of hepatitis B immunity: an observational cross-sectional study on medical students and resident doctors.

Hepatitis B virus (HBV) is a main cause of chronic and acute hepatitis. Healthcare workers (HCWs), including medical students and resident doctors, have an occupational risk of HBV infection. The study aimed to evaluate the long-term persistence of protective anti-HBs antibody levels in healthcare students and resident doctors at risk for occupational exposure to HBV at 15 years after primary vaccination course. Further objective was to evaluate the anamnestic response observed in non-seroprotected subjects receiving a booster dose. Data were collected from the clinical documentation filled in during the occupational medical check of medical students and resident doctors undergoing Occupational Health Surveillance by the University of Ferrara. Of the 621 included individuals, 27.7% had an anti-HBs concentration < 10 mIU/mL. Subjects vaccinated during infancy had more frequently a concentration < 10 mIU/mL than those vaccinated during adolescence (42.7% vs 6.9%; p-value < 0.001). Multivariate analysis confirmed the statistical significance of the vaccination age. 94 subjects who had an anti-HBs concentration < 10 mIU/mL received a booster dose. The proportion of subjects who had an anamnestic response was higher in those vaccinated in infancy rather than during adolescence (94.1% vs 77.8% respectively). These findings suggest that the anti-HBs concentration decreases below 10 mIU/mL more frequently in subjects vaccinated during infancy. Immunological memory seems to persist after the decline of the anti-HB titer, as observed in response to a booster dose. In conclusion, vaccinated subjects at increased risk of HBV infection should be monitored and a booster dose administered if anti-HBs titer is below 10 mIU/mL.

Colonization and Infection With Extensively Drug Resistant Gram-Negative Bacteria in Liver Transplant Recipients.

BACKGROUND: Infections due to extensively drug resistant Gram-negative bacteria (GNB) after solid organ transplantation are increasing in prevalence and are associated with high morbidity and mortality. Surveillance culture (SC) seems to be an important tool for extensively drug resistant GNB control. The aim of this study was to evaluate colonization rates and subsequent infections by XDR-GNB in liver transplant recipients. MATERIAL AND METHODS: This was a prospective cohort study in patients who underwent liver transplantation (LT) between January 2016 and January 2018. Data on demographics, extensively drug resistant colonization, and 3-month clinical outcomes were obtained. Colonization was defined as a positive surveillance culture (SC-perirectal) immediately before transplantation, once weekly after LT, and after intensive care unit discharge, with emphasis to carbapenem-resistant Gram-negative bacteria (CR-GNB). RESULTS: Forty-four patients who underwent LT were included in the study. Ten patients (22.72%) were colonized with CR-GNB prior to transplantation, and 7/10 (70%) developed infection due to the same pathogen (5 patients bloodstream infections, 2 patients pneumonia) during the study period. Intensive care unit length of stay was significantly longer in colonized with CR-GNB patients (P < .05). Mortality rate was higher in colonized patients (30%) than in noncolonized (11.76%) (P = .2). CONCLUSION: Our study results suggest an overall 70% risk of CR-GNB infection among colonized patients. Given the high mortality rate and the difficulty in treating these infections, further research to investigate and develop strategies to eliminate the colonization is needed.

Perioperative Chemoprophylaxis οr Treatment for Extensively Drug Resistant Gram-Negative Bacteria in Patients Undergoing Liver Transplantation Based on Preoperative Donor/Recipient Surveillance Cultures: A Prospective Study.

INTRODUCTION: The importance of preoperative donor/recipient colonization or donor infection by extensively drug-resistant Gram-negative bacteria (XDR-GNB) and its relation to serious post-transplantation infection pathogenicity in liver transplantation (LT) patients has not been clarified. AIM: Prevention of postoperative infection due to XDR-GNB with the appropriate perioperative chemoprophylaxis or treatment based on preoperative donor/recipient surveillance cultures in LT patients, as well as their outcome. MATERIALS AND METHOD: Twenty-six patients (20 male, 6 female) were studied (average preoperative Model for End-Stage Liver Disease score ≈15, range: 8-29) from January 2017 to January 2018. In all patients, blood, urine, and bronchial secretions culture samples as well as a rectal colonization culture were taken pre- and postoperatively, once weekly after LT, and after intensive care unit discharge. Recipients with positive XDR-GNB colonization and patients receiving a transplant from a donor with an XDR-GNB positive culture or colonization received the appropriate chemoprophylaxis one half hour preoperatively according to culture results. De-escalation of the antibiotic regimen was done in 2 to 5 days based on the colonization/culture results of the donor and recipient and their clinical condition. Evaluation for serious infection was done at 1 week and at 28 days for outcome results. RESULTS: Fourteen out of 26 recipients (53.8%) were positive for XDR-GNB colonization preoperative, with 2/14 (14.28%) presenting serious infection due to the same pathogen. Intensive care unit length of stay was significantly longer in colonized with XDR-GNB patients (P < .0001). The outcome of colonized patients was 6/14 (42.8%) expired, but only in 2/14 (14.2%) was mortality attributable to infection. CONCLUSION: Administering appropriate perioperative chemoprophylaxis and treatment may limit the frequency of XDR-GNB infections and intensive care unit length of stay and may improve the outcome in LT recipients.

Induction TPF followed by concomitant treatment versus concomitant treatment alone in locally advanced head and neck cancer. A phase II-III trial.

BACKGROUND: Platinum-based chemoradiation (CCRT) is the standard treatment for Locally Advanced Head and Neck Squamous-Cell Carcinoma (LAHNSCC). Cetuximab/RT (CET/RT) is an alternative treatment option to CCRT. The efficacy of induction chemotherapy (IC) followed by chemoradiation compared to chemoradiation alone has not been demonstrated in randomized clinical trials. The goals of this phase II-III trial were to assess: (i) the overall survival (OS) of IC versus no-induction (no-IC) and (ii) the Grade 3-4 in-field mucosal toxicity of CCRT versus CET/RT. The present paper focuses on the analysis of efficacy. MATERIALS AND METHODS: Patients with LAHNSCC were randomized to receive concomitant treatment alone [CCRT (Arm A1) or CET/RT (Arm A2)], or three cycles of induction docetaxel/cisplatin/5 fluorouracil (TPF) followed by CCRT (Arm B1) or followed by CET/RT (Arm B2). The superiority hypothesis of OS comparison of IC versus no-IC (Arms B1 + B2 versus A1 + A2) required 204 deaths to detect an absolute 3-year OS difference of 12% (HR 0.675, with 80% power at two-sided 5% significance level). RESULTS: 414 out of 421 patients were finally analyzed: 206 in the IC and 208 in the no-IC arm. Six patients were excluded because of major violation and one because of metastatic disease at diagnosis. With a median follow-up of 44.8 months, OS was significantly higher in the IC arm (HR 0.74; 95% CI 0.56-0.97; P = 0.031). Complete Responses (P = 0.0028), Progression Free Survival (P = 0.013) and the Loco-regional Control (P = 0.036) were also significantly higher in the IC arm. Compliance to concomitant treatments was not affected by induction TPF. CONCLUSIONS: IC followed by concomitant treatment improved the outcome of patients with LAHNSCC without compromising compliance to the concomitant treatments. The degree of the benefit of IC could be different according to the type of the subsequent concomitant strategy. CLINICAL TRIAL NUMBER: NCT01086826, www.clinicaltrials.gov.

Fulminant Epstein-Barr virus-associated hemophagocytic syndrome in a renal transplant patient and review of the literature.

We describe a rare fulminant case of Epstein-Barr virus-associated hemophagocytic syndrome (HPS) in a 37-year-old female renal transplant patient, indistinguishable from severe sepsis clinically and in the laboratory. HPS involves rapidly escalating immune system activation, resulting in a cytokine cascade, which can, especially in immunocompromised patients, lead to multi-organ failure, and even death. Thirty-two Herpesviridae-associated HPS cases in renal transplant patients have been reported and are reviewed. Overall mortality is 47% (15/32 cases).

Diffraction effects in length measurements by laser interferometry.

High-accuracy dimensional measurements by laser interferometers require corrections because of diffraction, which makes the effective fringe-period different from the wavelength of a plane (or spherical) wave λ0. By using a combined X-ray and optical interferometer as a tool to investigate diffraction across a laser beam, we observed wavelength variations as large as 10-8λ0. We show that they originate from the wavefront evolution under paraxial propagation in the presence of wavefront- and intensity-profile perturbations.

Determinants of adherence to seasonal influenza vaccination among healthcare workers from an Italian region: results from a cross-sectional study.

OBJECTIVES: Notwithstanding decades of efforts to increase the uptake of seasonal influenza (flu) vaccination among European healthcare workers (HCWs), the immunisation rates are still unsatisfactory. In order to understand the reasons for the low adherence to flu vaccination, a study was carried out among HCWs of two healthcare organisations in Liguria, a region in northwest Italy. METHODS: A cross-sectional study based on anonymous self-administered web questionnaires was carried out between October 2013 and February 2014. Through univariate and multivariate regression analysis, the study investigated the association between demographic and professional characteristics, knowledge, beliefs and attitudes of the study participants and (i) the seasonal flu vaccination uptake in the 2013/2014 season and (ii) the self-reported number of flu vaccination uptakes in the six consecutive seasons from 2008/2009 to 2013/2014. RESULTS: A total of 830 HCWs completed the survey. Factors statistically associated with flu vaccination uptake in the 2013/2014 season were: being a medical doctor and agreeing with the statements 'flu vaccine is safe', 'HCWs have a higher risk of getting flu' and 'HCWs should receive flu vaccination every year'. A barrier to vaccination was the belief that pharmaceutical companies influence decisions about vaccination strategies. DISCUSSION: All the above-mentioned factors, except the last one, were (significantly) associated with the number of flu vaccination uptakes self-reported by the respondents between season 2008/2009 and season 2013/2014. Other significantly associated factors appeared to be level of education, being affected by at least one chronic disease, and agreeing with mandatory flu vaccination in healthcare settings. CONCLUSIONS: This survey allows us to better understand the determinants of adherence to vaccination as a fundamental preventive strategy against flu among Italian HCWs. These findings should be used to improve and customise any future promotion campaigns to overcome identified barriers to immunisation.

Effects of lactoferrin, a protein present in the female reproductive tract, on parameters of human sperm capacitation and gamete interaction.

In a recent study, lactoferrin (LF) was detected in human oviductal secretion. The protein was able to bind to oocytes and sperm, and modulated gamete interaction. The aim of the present study was to investigate the effect of LF on parameters related to human sperm capacitation and sperm-zona pellucida interaction. Semen samples were obtained from healthy normozoospermic donors (n = 7). Human follicular fluids and oocytes were collected from patients undergoing in vitro fertilization. Motile sperm obtained by swim-up were incubated for 6 or 22 h under capacitating conditions with LF (0-100 µg/mL). After incubations, viability, motility, presence of α-d-mannose receptors (using a fluorescent probe on mannose coupled to bovine serum albumin), spontaneous and induced acrosome reaction (assessed with Pisum sativum agglutinin conjugated to fluorescein isothiocyanate), and tyrosine phosphorylation of sperm proteins were evaluated. Sperm-zona pellucida interaction in the presence of LF was investigated using the hemizone assay. The presence of LF did not affect sperm viability or motility, but caused a dose-dependent significant decrease in sperm α-d-mannose-binding sites, and the effect was already significant with the lowest concentration of the protein used after 22 h incubation. Dose-dependent significant increases in both induced acrosome reaction and tyrosine phosphorylation of sperm proteins were observed in the presence of LF. The present data indicate that LF modulates parameters of sperm function. The inhibition of gamete interaction by LF could be partially explained by the decrease in sperm d-mannose-binding sites. The presence of the LF promoted sperm capacitation in vitro.

Bloodstream infections caused by carbapenemase-producing Klebsiella pneumoniae among intensive care unit patients after orthotopic liver transplantation: risk factors for infection and impact of resistance on outcomes.

BACKGROUND: Carbapenem-resistant Klebsiella pneumoniae (CRKP) has emerged as an important cause of bloodstream infections in intensive care units (ICUs). The aim of this study was to determine risk factors for bloodstream infections caused by CRKP as well as risk factors for CRKP-associated mortality among ICU patients after orthotopic liver transplantation (LT). METHODS: The study cohort of this observational study comprised 17 ICU patients after LT with CRKP bloodstream infections. The data from these patients were matched with 34 ICU patients (1:2) after LT without CRKP infections. The 2 groups were compared to identify risk factors for development of CRKP infection and risk factors for mortality. RESULTS: Seventeen CRKP bloodstream infections occurred in ICU patients after LT from January 1, 2008, to December 31, 2011. In univariate analysis, primary liver disease and especially hepatitis C virus infection or hepatocellular cancer were significant factors for development of CRKP. Acute Physiology and Chronic Health Evaluation (APACHE II) score and Sequential Organ Failure Assessment (SOFA) score as well as CRKP bloodstream infection were predictors for ICU death (P < .05) in univariate analysis. CONCLUSIONS: CRKP bloodstream infections affect immunocompromised post-transplantation patients more. Bloodstream infections with CRKP along with APACHE and SOFA scores were predictors of death in ICU patients after LT.

Tigecycline for treatment of carbapenem-resistant Klebsiella pneumoniae infections after liver transplantation in the intensive care unit: a 3-year study.

BACKGROUND: This 3-year prospective, observational, single-center study was undertaken to describe prescription, microbiology findings, tolerance, and efficacy of tigecycline for carbapenem-resistant Klebsiella pneumoniae (CRKP) infections after liver transplantation in the intensive care unit (ICU). METHODS: All patients after liver transplantation treated with tigecycline for ≥3 days for CRKP infections in our ICU from January 1, 2010, to December 31, 2012, were studied. Patient characteristics, indication of treatment, bacteriology, and ICU mortality were collected. The main end points were clinical and microbiologic efficacy and tolerance of tigecycline. RESULTS: Over the study period, 8 men and 2 women (18 CRKP isolates), aged 54.3 ± 7.7 years, were included in the study. Acute Physiology and Chronic Health Evaluation and Sequential Organ Failure Assessment scores on ICU admission were 13.7 ± 2.7 and 10 ± 2.2, respectively. In 7 isolates, tigecycline was prescribed for CRKP blood stream infection (BSI), in 6 for complicated intra-abdominal infection (IAI), in 2 for ventilator-associated pneumonia (VAP), in 2 for surgical site infection, and in 1 for urinary tract infection. In 4 cases, tigecycline was prescribed for secondary BSI followed by VAP and/or IAI. All isolates were susceptible to tigecycline, 83.4% to colistin, 44.5% to gentamicin, and 27.8% to amikacin. In 2 patients, tigecycline was prescribed as monotherapy. Three patients had clinical failure. The microbiologic response rate was 70%. Superinfection was detected in 5 patients, and Pseudomonas aeruginosa was the most frequently isolated pathogen. Tigecycline was generally well tolerated. The ICU mortality rate was 60% with attributable mortality rate 30%. CONCLUSIONS: Our pilot study suggests that tigecycline shows a good safety and tolerance profile in patients with CRKP infections in the ICU after orthotopic liver transplantation. Limited therapeutic options for such infections leave physicians no choice but to use tigecycline for off-label indications such as urinary tract and blood stream infections.

Polarization delivery in heterodyne interferometry.

Optically heterodyned laser interferometry, as applied to measuring linear displacements, requires different optical frequencies to be encoded onto unique polarization states. To eliminate non-linear contributions to the interferometer signal, the frequency difference must be introduced after beam splitting and the interfering beams must be recombined via spatially separated paths. The polarization jitter of the frequency-shifted beams still originates a noise in the beat-signal phase. A formula is given expressing the noise amplitude in terms of the illuminating beam's extinction ratio.

Effects of lasalocid and intermittent feeding of chlortetracycline on the growth of prepubertal dairy heifers.

Forty Holstein heifers entered the 12-wk study at approximately 12 wk of age. At enrollment, heifers were blocked by birth date and assigned to 1 of 4 treatments: (1) carrier (30 g; control); (2) lasalocid + carrier (1 mg/kg of body weight; L); (3) chlortetracycline + carrier (22 mg/kg of body weight; CTC); (4) L + CTC + carrier (CTCL). Heifers on CTC and CTCL were provided treatment Monday through Friday and carrier only on Saturday and Sunday. These heifers were provided their respective treatment during wk 1 to 4, 6, and 10; wk 5, 7 to 9, and 11 to 12 heifers were provided the nonmedicated carrier. Heifers were individually fed a total mixed ration with treatments top-dressed at 1200 h daily. Dry matter intake was monitored for each heifer and feed provided was adjusted according to individual intakes. Skeletal measurements were taken weekly and blood samples were obtained every Monday, Wednesday, and Friday. Blood samples were analyzed for thyroxine concentration via radial immunoassay. Heifers supplemented with L had lower average daily gain , overall body weight gain, and trends for lower daily body length gain and overall girth gain compared with CTC heifers, but similar to control and CTCL heifers. Heifers fed L had lower hip height gain and overall hip height gain compared with CTCL heifers, but similar to control and CTC heifers. Heifers fed L had lower overall withers height gain compared with control heifers, but similar to CTC and CTCL heifers. No treatment effect on thyroxine concentrations was observed. These data indicate that L did not increase growth. Results from this experiment indicate that supplementing heifers with L was not beneficial and no benefits to supplementing heifers with CTC or the combination of CTC and L were evident compared with control heifers. Heifers in this study experienced minimal health problems and were regarded to be under low stress levels. Supplementing CTC and L may be beneficial to growing heifers under conditions where disease exposure and stressors are greater.

Course and outcome of renal transplant recipients admitted to the intensive care unit: a 20-year study.

BACKGROUND: Renal transplantation represents the main treatment for end-stage renal disease. The goal of this study was to evaluate the course and outcome of renal transplant recipients admitted to the intensive care unit (ICU) and to analyze factors determining prognosis and mortality. METHODS: The demographic features, data admission characteristics, and ICU courses of all renal transplant recipients admitted to our ICU from 1992 to 2012 were evaluated to analyze factors for mortality. RESULTS: Eleven women and 50 men of mean age 45.5 ± 12.5 years were included in the study. Acute Physiology And Chronic Health Evaluation (APACHE II) and Sequential Organ Failure Assessment (SOFA) scores on ICU admission were 20 ± 5.7 and 8.5 ± 3.5, respectively. The main reasons for admission were as follows: sepsis (n = 27) or immediate postoperative complications (n = 16). Thirty-five patients during their ICU stay required hemodialysis and 34 needed catecholamines. The mortality rate was 42.6%. APACHE II Score, dialysis requirement, and sepsis as a reason for ICU admission were independently related to the mortality. CONCLUSIONS: The mortality rate was higher than that of the general ICU population (42.6% vs 30%). The main reason for ICU admission of renal transplant recipients was sepsis.

Infections related to renal transplantation requiring intensive care admission: a 20-year study.

INTRODUCTION: The aim of this study was to evaluate infection complications as the reason for intensive care unit (ICU) admission among transplant recipients. METHODS: We studied all renal transplant recipients with infectious complications admitted to our ICU from 1992 to 2012:44.3% of all renal transplant recipients admitted to ICU. The epidemiology and prognosis of infectious complications requiring ICU admission were evaluated with analysis of mortality factors. RESULTS: The 22 men and 5 women included in this study showed a mean age of 42.7 ± 12.3 years. The Acute Physiologic and Chronic Health Evaluation II and Seguential Organ Failure Assessment scores on ICU admission were 20 ± 4.6 and 8.6 ± 3.9, respectively. The main infections complications requiring ICU admission were cytomegalovirus pneumonia (n = 15) and aspergillus pneumonia (n = 4). Sixteen patients required hemodialysis and 14, catecholamine support upon ICU admission owing to septic shock. The mortality rate among study patients was 62.9%, versus 26.5% for noninfectious renal transplant recipients requiring ICU admissions. Catecholamine support at ICU admission was independently related to mortality. CONCLUSION: The mortality rate of renal transplant recipients admitted to ICU owing infection complications was higher than that of noninfected renal transplant patients. These data suggest that infections and septic shock in renal transplant recipients requiring ICU admission worsen their outcome significantly.

Decision making for knee replacement: variation in treatment choice for late stage medial compartment osteoarthritis.

BACKGROUND: Patients with medial unicompartmental osteoarthritic disease of the knee requiring arthroplasty can be treated with either Total or Unicompartmental Knee Replacement (TKR or UKR). Currently, the decision to choose one operation over another is not well defined and may depend on the profile of the surgeon consulted. We tested the hypothesis that different surgeons will select different treatment for identical patients requiring knee replacement. METHOD: Four different surgeons, representing four different levels of expertise, made a forced choice decision of whether they would perform TKR or UKR based on radiographs alone and subsequent additional clinical information including gender and age, in 140 patients. Individual surgeon repeatability was tested by repeat assessment 3 months later. RESULTS: The knee surgeon from the UKR design centre would have performed a UKR in up to 88% of the patients. The remaining surgeons would have performed UKR in 29-48% of patients; a variation in decision making of up to 59%. Additional clinical information had little effect on decision making with surgeons maintaining their radiographic based choice in 80 to 87% of cases. The repeatability study showed high within surgeon consistency for treatment choice. CONCLUSION: Surgeons, given identical information, do not concur on treatment for patients with the same pathology. The decision making process appears heavily influenced by radiographic findings but individual surgeons are consistent with their own treatment choice. The study shows that consensus treatment for medial osteoarthritis of the knee remains in question.

Determination of the Avogadro constant by counting the atoms in a 28Si crystal.

The Avogadro constant links the atomic and the macroscopic properties of matter. Since the molar Planck constant is well known via the measurement of the Rydberg constant, it is also closely related to the Planck constant. In addition, its accurate determination is of paramount importance for a definition of the kilogram in terms of a fundamental constant. We describe a new approach for its determination by counting the atoms in 1 kg single-crystal spheres, which are highly enriched with the 28Si isotope. It enabled isotope dilution mass spectroscopy to determine the molar mass of the silicon crystal with unprecedented accuracy. The value obtained, NA = 6.022,140,78(18) × 10(23) mol(-1), is the most accurate input datum for a new definition of the kilogram.